There are various use cases for secure shell port forwarding. In most cases, SSH port forwarding is used to create an encrypted connection between a local computer (the local host) and a remote computer. The use of this virtual network allows certain restrictions on access to be bypassed. It will look like you are on this network, when you are in reality just accessing it using the SSH tunnel. This is similar to a Virtual Private Network (VPN) but is nonetheless different — try not to mix the two up.
If you’re transporting data from services that use an unencrypted protocol, you can use SSH forwarding to encrypt the data transfer. A SSH File Transfer Protocol, SFTP for short, will be used for this. SSH tunnels also offer increased security when you’re surfing on unfamiliar networks, for example in a hotel or coffee shop. SSH keys use asymmetric encryption and provide an even higher level of security.
It’s important to note that SSH tunneling is frequently used by hackers, who build backdoors in internal networks so that attackers can easily access internal data.